This application relates to an oil reservoir for a gearbox, wherein the shape is optimized to ensure adequate oil flow even when a vehicle carrying the gearbox is put through extreme changes in orientation.
Modern aircraft, and in particular helicopters, must be able to perform a variety of extreme maneuvers. They must be able to have nose up and nose down, and left and right inclination attitudes. In addition, the attitudes may be combined between nose up/down and left/right inclination.
One component that is typically mounted on modern helicopters is an APU, or auxiliary power unit. An APU is a small gas turbine engine which generates electrical power. The APU includes a gear train mounted in a gear housing. The gear train is provided with a lubrication system, including a lube pump moving oil from an oil reservoir across the gear train.
An inlet tube takes oil from the reservoir and delivers it to the pump. The extreme changes in attitude that can occur with the use of such a system on a helicopter raise challenges with ensuring there is an adequate oil level to supply oil into the inlet tube. On the other hand, it is also important to not have too high an oil level. Typically, a designer would not want the gear train to be immersed in the oil.